Pneumatic form for glove dipping



Oct. 4, 1932. P. H. WATKINS 1,881,005

PNEUMATIC FORM FOR GLOVE DIPPING Filed Oct. 11. 1927 I N VENTOR Iarhe J2 I l/aiifins BY I A ORNE) Patented Oct. 4, I932 UNITED STATES PATENT OFFICE- PARKE H. WATKINS, F LEONIA, NEW JERSEY, ASSIGNOR TO NATIONAL INDIA R'UiBBEB COMPANY, OF BRISTOL, RHODE ISLAND, A CORPORATION OF RHODE ISLAND PNEUMATIC roam non GLOVE mrrme Application filed October 11, 1927. Serial No. 225,463.

This invention relates to method and apparatus for coating articles with rubber.

I rubber glove.

' and a glove in position thereon;

More particularly it relates to a method and apparatus for manufacturing dipped rubber articles inert toward the usual solvents and havin a flexible base.

It has been customary to manufacture dipped rubber gloves by dipping a form made of a rigid material such as porcelain into a solution of rubber. The solvent is then evaporated from the coating of rubber upon the form and the'glove shaped rubber is vulcanized. These gloves have been suit able for use of surgeons, linemen, etc. Need has been felt for a relatively inexpensive glove which shall have. the waterproofing properties of a dipped rubber glove, be resistant to organic solvents, have the strength giving qualities of a glove made of fabric and which can be more readily drawn on and off the hand .of the wearer than the usual It is an object of this inventionto provide a dipped rubber glove having a flexible base made of fibrous material. A further object is to provide 'a rubber article which is resistant to solvents. Another object is to provide an improved process for forming present in the base. Another object is to provide a form which can be easily inserted into and removed from the base.

For a complete disclosure of the nature and objects of the invention, reference is had to the accompanying drawing in which:

Fig. 1 is a front elevation of the form with 1 1g. 2 is a front elevation of-the complete form with parts broken away to indicate the framev thereof I Fig. 3 is a section onthe line 33 of Fig. 1;

the skeleton frame of cotton'fabric, although any other fabric or suitable flexible material such as heavy crepe paper can be used. Ordinary fabric cloth is covered with rojections of a fine fuzz and in the process of dipping in rubber dispersion, to be later described, the projecting fuzz will take a' deposit of the rubber composition 'With the result that a rough, rubber surface is formed on the fabric. The cloth is thereate It is accomplished by dipping the cloth in a hot roughly 10% solution of ammonium alum,

wringing out the excess solution, dipping in hot approximately 2% ammonium s'tearate, wringing out the excess, dipping in an ammonium alum, rinsing, wringing out the excess and rinsing in cold water. The fabric is then dried.

The fabric is now out into blanks and made up into gloves or mittens, or any desired articles which are to constitute a base or backing and be coated with a dispersion of rubber.

The fabric glove is placed upon a pneumatic form and is dipped into a rubber dispersion.

The form comprises a block 1 formed of wood, metal or'other suitable material from which extends a plurality of rods 2 which are to constitute the supporting frame for the fingers and thumb of the form. The rods 2 are preferably made of flexible material such as steel, aluminum, etc., and are secured to the block 1 by nuts 3 screwed thereon and bearing against metal washers 4 and rubber washers 5. At their outer ends, the rods carry a knob 6 of sufficient size and shape to support the ends of the fingers and thumb without breaking through the same. A rubber glove, preferably a dipped rubber glove 7, is positioned over the frame and is cemented to the block 1 in air tight relation thereto. In cementing the rubber glove to the block, it is desirable to first dip the block in a dispersion of rubber such as latex and then to coat I joints,'t

f as

t inithiiibbi eta-ea, the} that th a i h' pl e-@- A; ui l comp fl n spr y g-1 g-" lmplaoe of semi-cured latex, un-

g cured latex or an artificial dispersion'of rubr r httndLSO Par s f. zb by 5 weight. The 1 rubber'- cem ent serves to 1 1n-- crease the .grip of the rubbe'r dispersion on iforithe rubber cement comprises parts of Y the block ;1. 111 order to'i'nflafcan'd deflate the form, thereha's been provided awake-stem S-Which passes jthroughth'e block 1 with thed m base flange 9 thereof bearing against a rubber washer 10. A nut 11 tightensi 'thejvalvestem;

uponthe block. The purpfi of. using rub,

ber washers when securing therodsandvalvee stem in osition, is to'maketheij'omts. air

1' tight. he m of dipping the bl'ock in a dispersion of ru ber composition extending over the'blocka-nd age.

air tight, flexible, expansibleform. ;Air, water or any suitable material can be inserted through the valve stem to inflate the form. The rods 2 have .been disposed suflicie'ntly separated so that the fingers of the form will be spaced apart thus permitting access between the fingers of the form. Theglove when inflated has a tendency to bulge outwardly at the palm 'and back of the form.'

To offset'this tendency, a reinforcement 14 of fabric .or other suitable non-yielding material is secured to the palm of the glove or 'back,'or both as desired. This reinforcement can be cemented in place with rubber cement..

.Before assembling the fabric backing 15 upon the form, it is desirable to deflate the form, after which the backing can easily be slipped into position thereon. The form is then inflated until it completely fills the backing, which assumes a smooth unwrinkled appearance. The operation of coating the backing with rubbercomposition can now be undertaken. A latex composition is prepared into which the form and backing is dipped. A suitable composition comprises:

Parts by s K weight Dry-rubber (as semi-cured latex containing40% solids).. 100 Zinc oxide a .Lithopone 40 Ultramarine blue Glue 20 Sulphonated castor oil 5' b5 Sulphur 2 .Zinc dimethylamine dithiocarbamate- 'Sodiumtsilicate 1 Nujol emulsion; 25 Nekal 2 Sodium resinate 1% This composition forms a dispersion of rubber composition in water containingfabout 55% solids. To this composition should be added 'suflicient water to make a dispersion containing approximately 45% solids, there- This combination-of elements constitutes an" ber'can'ybe used; Thefzincfoxide, lithopone and '1 'ultrainarine blue serve as j coloring agents. The glue "and the sodium silicate function" as stabilizers The 'sulphonated 'castor' on 'ves a smoothsu'rface to the final ippmg. e nekal functions as both-a stabilizer and a-thinning agent,.w'hile the sodium resinate serves "as a th nning agent. Triso-.

diurn' phosphate. can be substituted for the "nek'al asdesiredL' -Thenujol-serves as a soft-- ening'jagent and if a dark colored glove is made, a cheaper -'oil,-fsuch" as spindle oil, can

:be' 1 substituted. therefori Anyf'soap can be I g I substituted fora-the zsodiumresinate, the purereby decreasing the danger of lcakj posego'fwhichi-is ,to aid. in corporatin'g the emulsion into the dispersion. In applying I the invention to, themanufacture of a solvent resistant article anon-soluble soap is preferably substituted for the sodium resinate or the soap is omitted entirely. The glue is of tion. Thisinitizil step is desirable for the reason that a thin coating is" deposited and -the rubber composition does. not strike through the fabric. The initial coating is applied in athin layer and is permitted to dry for a short time, such as ten minutes. A second coating is applied by spraying and the treated glove is allowed to dry for a slightly longer period. If desired, other coatings may be applied b spraying and reinforcement between the ngers is provided for by spraying this part of the love an additional number of times. The t inly coated glove is thenimmersed in the latex composition, is removed, and allowed to drain with the fingers projecting downwardly until nearly all of the excess latex has dripped away. The glove is then held in reverse position for a length of time suflicient for the thick drop which has formed at the end of each finger to spread out evenly over the finger. This can complete the dipping operation or, if desired, the treated glove can be dried and again dipped as before.

The step of initially spraying the fabric backing with latex composition to prevent striking through of. the. composition, can be omitted, if desired, and the initial rubber coatings formed on the backing without striking through ina manner to be now described. Factors affecting the tendency of weave of the fabric, t

the latex composition to strike throu gh'the .sure varies in different parts of the body of latex composition increasing with the depth.

' entire backing-is coated with rubber compo-' fects building up of a layer of rubber com position thereon to the required thickness, as. previously described. Latex composition can ment of any portion of the article.

With the latex com osition described and using a closely woven acking, 'it has been'found that the backing can be dipped into the composition to a depth .of-approximately three to six inches withgut causing a striking through of the backing by the latex composition. Ac-

cordingly, the backing is first dipped to a depthof approximately three to six inches below the surface of the liquid, after which the backing is withdrawn and'partially, at

least, dried. The partially coated backing can be dipped approximately-three to six inches more deeply in the latex domposition at the next dipping and the progressive dipping can be repeated indefinitely until the sition. Repeated dipping of the .entirely coated hacking into the latex composition efbe sprayed upon the dipped backing ifd-esiredin order to provide for local reinforce- The dipped glove is passed through a chamber containing vapors of acetic acid or mixed acetic acid and alcohol in order to'co agulatc the latex. Alternatively, other metheds of coagulating can be employed, such as canization' for approximately one hour at 220 F. under suitable pressure orunder such dipping the glove in a acetic acid solution, or the glove may be dried. without using acid. v

The rubber coated glove is-subjected to vulconditions as may be necessary depending upon the particular compound and acceleratorused. Q

In case it is not desired to rubber coat the entire backing, as for example, the wrist portion when the backing has been fabricated vdipping or both, after which therubbercomposition adhering to the backing is dried. The rubber coating-on the backing can now be coagulated and vulcanized in the manner previously described. The temporary covermg 18 now removed after severing the same or otherwise loosening the covering from the backing. If desired, the temporary covering can be removed prior to the step of vulcaniz'ing the rubber composition. Upon removal of the temporary covering. there is left an area of backin which is uncoated by rubber composition, .t e, rubber composition terminating sharply andcl'eanly at the uncoated area. The uncoated portion of-the glove has been maintained perfectly .clean m'every respect without the exercise of care by the operator.- i i p a a In order to render theglove more inert towards solvents and to otherwise improve the same, itmay be exposed to the action of a halogen such as bromine-or chlorine for a length of time sufiicient to form a coating of rubber-halide on the surface of the glove. For example the glove can be dipped in an approximately. 1/10 to 3% solution of bromine in carbontetrachloride. The excess halogen is removed by washing' with water.

By the method as outlined, there has been provided a fabric-lined dipped rubber glove in which the rubber composition has the intimate association with the fabric which is secured by dipping in latex. By dipping the fabric backing in latex, the breaks in the fabric and the needle holes, are all coated over with rubber forming a glove which is I waterproof. The protecting coating of rubber composition lessens deterioration of the fabric for 'the reason that it maintains it unaffected by the'liquids in whichthe article may be dipped. The glove can be subjected to: comparatively heavy strains without injury thereto by virtue of the strength de- "rived from the fabric base. The glove is inexpensive to manufacture and canbe fabricated rapidly and accurately by. ordinary sewing. The coating of vulcanized rubber composition derived'from a deposit of latex is relatively i solvents, s uclras gasoline, naphtha, benzol, carbon tetrachloride, and mineral fractions for the-reason that the rubber particles have never been broken down in the usual milling operations. When the surface of the glove has been halogenated, it 'is particularly inert towards solvents. By selection of pi merits whichare inert toward solvents the resistance of the glove toward solvents has been increased. The glove has a smooth surface and is free from wrinkles. It is suitable for use yivlheirever liquids such as acids must be hane While the invention has been described as making use of a dispersion of rubber for coating the backing, suitable rubber solutions can be employed, if desired, and some of the advantages of the invention realized. In place of fabric for the backing or the temporary covering, other supporting materials such. as

rt toward the usual rubber Lil heavy crepe paper can be used. When a smooth finished surface is desired, the fabric used in the backing is preferably calen v dered prior to the proofing operation. When arough surface or a surface having a trace of a design is desired, a raised figure at suitable intervals can be formed in the fabric or other backing.

' The invention is not restricted to the manufacture of gloves, mittens, or other wearing vapparel for the hands, but can be applied to the manufacture of any rubber coated article which is designed to have a reinforcing base. Among sucharticles may be mentioned shoes, rubber tubing, bathing caps, etc. The invention is particularlyapplicable to the manufacture of rubber coated fabric which is made into articles designed to be subjected to the action of solvents or their vapors such for example as the breather bag which is used for preventing loss of vapors from oil tanks. Thesebags can be formed of fabric or other suitable material coated with solvent resistant rubber composition.

Having thus described my invention, what I claim and desire to protect by Letters Patent is:

1. A form for repeatedly making dipped rubber articlescomprising a flexible frame, an expansible covering for the frame and means for expanding the covering.

2. A form for making dipped rubber articles of handwear comprising a frame having spaced projections, a glove shaped covering carried by the frame with the fingers andthumb thereof supported and held apart by and means for expanding said projections, the covering.

Si ned at New York, county and State of New. ork, this 6th day'of October, 1927 PARKE H. WATKINS. 

